The below shows a square ABCD and an equilateral triangle DPC:
Nick makes the chart shown below to prove that triangle APD is congruent to triangle BPC:
Which of the following completes Nick's proof?
A) P is the vertex of the equilateral triangle
B) Sides of equilateral triangle DPC are equal
C) Triangle APB is an isosceles triangle
D) DC is the base of an equilateral triangle
